Numerous chemotherapeutic agents will be tested for their relative ability to transform the mouse cell line 10T1/2 C1-8. Also various possible mechanisms for transformation with ara-C and FUdR in the S phase of the cell cycle will be studied using the same mouse cell line. The rapidity of producing increased fibrinolysis following exposure to chemotherapeutic agents which produce malignant transformations such as ara-C and FUdR will be studied and correlated with the time at which there is morphologic expression of malignancy.